1. Field of the Invention
This invention relates to a method for producing semi-cylindrical friction bearing parts or shells from ribbon-like composite laminate material, wherein the composite laminate material is fed to a processing line and subjected, in a multiplicity of successive stations of a processing machine, to various processing steps, each designed as a work stroke, until the friction bearing parts are finished, except for machining of their sliding surfaces. The parts are transported or fed for this purpose, from one station to another of the processing line.
The invention also relates to a machine for the execution of this method, in which there are provided a common drive mechanism for the simultaneous automatic opening and closing of dies in the various stations, and a powered transporting mechanism for the composite laminate material and the workpieces formed thereof, which transporting mechanism traverses the series of successive stations.
2. Description of the Related Art Including Information Disclosed Under 37 CFR .sctn..sctn.1.97-1.99
Methods and machines of this kind, namely for the manufacture of friction bearing parts, in which a ribbon of laminate material is processed into friction bearing parts in a multi-station processing line are already known. Reference is made to German Printed Application No. DE-AS 1 677 165, German Publication No. DE-OS 2 174 633, German Printed Application No. DE-AS 2 235 933, U.S. Pat. No. 3,206,830, British Patent No. 336,333, and British Patent No. 663,476. In all of these known methods and machines the ribbon material is subjected to a considerable number of machining operations before being cut into individual plates or friction bearing elements. The drawback thereof is that the dimensional changes resulting from the various machining operations, in particular stamping and upsetting operations on the ribbon material, are additive in the direction of ribbon travel. More specifically, as the length of the processed ribbon material is increased, due to an increase in the number of machining stations, the alignment accuracy of the ribbon with respect to the tools or dies contained in each station becomes more and more imperfect. But it is of decisive importance for precision machining that there be exact alignment of the ribbon section that is being processed with respect to the tools or dies contained in each station. As a further drawback, it must be added that machining operations involving chip removal from a continuous ribbon of material cannot be effectively carried out in practice, due to problems in guiding of the unprocessed ribbon material, and the inaccessibility of cutting tools to the workpiece. Furthermore, it was hitherto impossible to remove the chips generated from the ribbon material with the required safety and completeness, as is necessary for a safe and exact completion of the work cycle, and for the attainment of adequate precision. While it is known from German Publication No. DE-OS 29 30 435, in a comparable method, to produce friction bearing parts by first scribing plates by impressing transversely extending grooves into the continuous ribbon material, and then machining the ribbon material in the area of the individual plates, and thereafter before the final forming of the semi-cylindrical friction bearing parts, deepening the impressed groove substantially on one side of the ribbon material by means of a cutting tool moved transverse to the ribbon material, this prior method is not practical because in order to be able to transform the frontmost, scribed plate into a semi-cylindrical friction bearing part and at the same time separate it from the ribbon material, the prior method is not properly engineered for, nor does it achieve, successful machining of the ribbon material or the individual plates cut from the ribbon material by chip removal. This is true regardless of the type of friction bearing part of the sliding layer which is preformed on the ribbon material.